Plastics composition

ABSTRACT

Aromatic hydrocarbon oligomers of the formula 
     
         (A).sub.a (--CH.sub.2 --).sub.b [--CH.sub.2 (OCH.sub.2).sub.m OCH.sub.2 
    
      --] c  (--CH 2  X) d   
     wherein A is at least one aromatic hydrocarbon or heterocyclic residue, X is OH or a derivative thereof, a is 2 to 20 but equals b+c+1, b is 0 to 19, c is 0 to 19, d is 0 to 2a and m is 0 to 10, there being at least two (--CH 2  X) groups per molecule, the group each --CH 2  O--CH 2  -- portion of the group counting as (--CH 2  X) for this purpose, are suitable as non-volatile fire retardent agents in chlorine-containing aliphatic polymers, copolymers or polyblends, which contain an ester of an phosphorus acid.

The present invention relates to flame retardant polymer compositions, and it relates in particular to chlorine containing aliphatic polymers, copolymers and poly blends.

In the German Offenlegungsschrift No. 2,648,701 there is described a composition comprising a chlorine-containing aliphatic polymer and (a) an ester of a phosphorus acid and (b) a compound of the formula

    R(CH.sub.2 X).sub.n

in which R represents an aromatic hydrocarbon or heterocyclic containing residue, n is an integer of at least 2 and each X is the same or different and represents a leaving group.

We have now found that certain oligomers when used as the compound R(CH₂ X)_(n) provide in conjunction with the phosphorus acid ester compositions having good plasticising properties and the oligomers also have the advantage of lower volatility. At the same time the fire retardant effect of the phosphorus compounds in the chlorine containing aliphatic polymers can be greatly improved by the use of certain supplemental additives. As a result, either a greater fire resistance can be achieved without increasing the phosphorus content of the polymer or the same fire resistance can be achieved with a lower phosphorus content.

Accordingly, the present invention provides compositions comprising a chlorine-containing aliphatic polymer, copolymer or poly blend, and (a) an ester of a phosphorus acid, and (b) an aromatic hydrocarbon oligomer of the formula.

    (A).sub.a (--CH.sub.2 --).sub.b [--CH.sub.2 (OCH.sub.2).sub.m OCH.sub.2 --].sub.c (--CH.sub.2 X).sub.d                            I

wherein A is at least one aromatic hydrocarbon or heterocyclic residue, X is OH or a derivative thereof, a is 2 to 20 but equals b+c+1, b is 0 to 19, c is 0 to 19, d is 0 to 2a and m is 0 to 10, preferably 0-5, most preferably 0, there being at least two (-CH₂ X) groups CH₂ OCH₂ per molecule, each portion of the group [--CH₂ (OCH₂)_(m) OCH₂ --]_(c) counting as (--CH₂ X) for this purpose.

It should be noted that the values of a, b, c, d and n are average values for the average molecule of formula I.

Examples of aromatic residues A are benzene, naphthalene, furan, anthracene, biphenyl and diphenyl ether. The aromatic residue A may be unsubstituted or substituted by one or two substituents. It is preferably unsubstituted, but if it is substituted it preferably carries only one substituent. Suitable substituents include halogen, alkyl groups with 1 to 4 carbon atoms, haloalkyl groups with 2 to 4 carbon atoms, and the group OR³ where R³ is hydrogen, alkyl with 1 to 4 carbon atoms or acyl with 1 to 4 carbon atoms.

The compounds represented by formula I are mixtures of oligomers with a range of molecular weights. The residues A are linked by (--CH₂ --) or [--CH₂ (OCH₂)_(m) OCH₂ --] groups, these two linking groups being connected only to a residue A and not to each other. The groups (--CH₂ X) are connected to a residue A.

Preferably greater than 50 mol % of residues A are derived from naphthalene; most preferably more than 75 mol % of residues A are derived from naphthalene.

Oligomers which are preferred are those having a number average weight of 300 to 3500, more preferably those having a number average molecular weight of 350-1500, most preferably 400 to 1000. It is preferred that the naphthalene residues are linked by (--CH₂ OCH₂ --) and that these links should be attached to the positions 1,4; 1,5; 1,6; 1,7; 2,5; 2,6 or 2,7 on the naphthalene residue. It is most preferred that the links should be attached to the 1,4 or 1,5 positions on the naphthalene residue.

Non-limiting examples of particular oligomers of structure II are those linked by the group --CH₂ OCH₂ -- and having two or more --CH₂ X groups per molecule. Preferred structures which can be present as a component of the oligomer mixture are shown below. The group --CH₂ OCH₂ -- being counted as a --CH₂ X group. ##STR1##

Where m=0 or 1, and X=OH ##STR2## Specific Examples of oligomers which can be present as components of the oligomer mixture are listed in Table A ##STR3##

                                      Table A                                      __________________________________________________________________________     No                                                                               a b c n d R.sup.4                                                                             R.sup.1                                                                           R.sup.5                                                                             R                                                     __________________________________________________________________________     1 0 0 1 0 2 --   -- --   CH.sub.2 OH                                           2 1 1 1 0 2 --   -- --   CH.sub.2 OCH.sub.3                                    3 2 1 2 0 2 CH.sub.3                                                                            -- CH.sub.3                                                                            CH.sub.2 OH                                           4 3 2 2 0 2 CH.sub.2 Br                                                                         -- CH.sub.2 Br                                                                         CH.sub.2 OH                                           5 4 1 4 0 2 CH.sub.3                                                                            -- CH.sub.3                                                                            CH.sub.2 OCH.sub.3                                    6 5 1 5 0 2 --   -- --                                                         7 6 2 5 3 2 --   -- --   CH.sub.2 OH                                           8 8 2 6 0 2 CH.sub.3                                                                            CH.sub.3                                                                          CH.sub.3                                                                             ##STR4##                                             9 8 1 8 0 2 --   -- --                                                                                   ##STR5##                                             10                                                                               5 1 5 6 2 --   -- --   CH.sub.2 OH                                           11                                                                               1 0 2 0 2 --   -- --   CH.sub.2 OH                                           __________________________________________________________________________

X represents OH or a derivative thereof. Non-limiting examples of derivatives include --OR, ##STR6## phenoxy, benzyloxy, or alkylphenoxy. Other examples of such derivatives may be represented by the formulae ##STR7## Where W is O, S, NH or NR¹, but is preferably O,Z is H, R, OR¹, SR, NH₂, NH--R¹ --, N R¹, N R¹ R², but preferably is H or R. Y, Y¹, are independently O, NH, ##STR8## --S--, or are absent but preferably O or S. L is O or S or absent, but is preferably O. M is O or is absent, but is preferably O R represents a straight or branched chain alkyl having 1 to 12 carbon atoms, preferably 2 to 4, cycloalkyl or cycloalkenyl having 5 to 12, preferably 6, carbon atoms. R may be optionally substituted by one or more halogen, hydroxy, epoxy, nitro, amine, amide, ether, carboxyl or ester groups or combinations thereof, but is preferably unsubstituted. R¹ and R² have the same significance as R and may be the same or different. However, X is preferably --OH--, --OCH₃ ; --OC₆ H₅, ##STR9## and most preferably is OH.

The phosphorus acids include derivatives of phosphoric acid, phosphonic acid, phosphinic acid, phosphorous acid or their dehydration products. The acid groups in partial esters may be present as free acid groups, but preferably as their salts, e.g. as alkali metal or ammonium salts.

Non limiting examples of the phosphorus esters based on phosphoric acid are:

1 triphenyl phosphate

2 cresyl diphenyl phosphate

3 phenyl xylyl phosphate

4 tri-tolyl phosphate

5 tri-xylyl phosphate

6 tri-ethyl phenyl phosphates and phenyl/ethylphenyl phosphates

7 phenyl/isopropyl phenyl phosphates (for example those sold under the trade name Reofos 95, 65 and 50, and prepared as described in U.K. Patent No. 1,146,173).

8 phenyl/sec-butyl phenyl phosphates

9 phenyl/p-t-butyl phenyl phosphates

10 di(o-cumyl phenyl)phenyl phosphate

11 di(p-benzyl phenyl)phenyl phosphate

12 tri-(p-t-butyl phenyl)phosphate

13 tri-(p-nonyl phenyl)phosphate

14 tri-(p-t-amyl phenyl)phosphate

15 tri-(p-chlorophenyl)phosphate

16 tri-[o-(bromo isopropyl)phenyl]phosphate

17 tri-[p-(bromo isopropyl)phenyl]phosphate

18 diphenyl hydrogen phosphate

19 di(o-isopropyl phenyl)hydrogen phosphate

20 phenyl di-hydrogen phosphate sodium salt

21 diphenyl hydrogen phosphate sodium salt

22 diphenyl-(2-bromoethyl)phosphate

23 diphenyl-(2-chloroethyl)phosphate

24 diphenyl-(2,3-dibromopropyl)phosphate

25 diphenyl-(2,3-dichloropropyl)phosphate

26 diphenyl-n-octyl phosphate

27 diphenyl-n-decyl phosphate

28 phenyl n-octyl hydrogen phosphate ammonium salt

29 phenyl(2,3-dibromopropyl)phosphate potassium salt

30 phenyl di(2-bromoethyl)phosphate

31 phenyl di(2-chloroethyl)phosphate

32 phenyl di(2,3-dichloropropyl)phosphate

33 phenyl di(2,3-dibromopropyl)phosphate

34 phenyl di-n-octyl phosphate

35 phenyl di-n-decyl phosphate

36 di-n-decyl hydrogen phosphate

37 di(2-bromoethyl)hydrogen phosphate sodium salt

38 2,3-bromopropyl methyl hydrogen phosphate

39 tri(2-chloroethyl)phosphate

40 tri(2-bromoethyl)phosphate

41 tri(2,3-dibromopropyl)phosphate

42 tri(2,3-dichloropropyl)phosphate

43 tri-octyl phosphate

44 tri-decyl phosphate

45 tri-allyl phosphate ##STR10##

Non limiting examples of esters based on phosphonic acid are:

47 diphenyl phenyl phosphonate

48 di-(p-bromophenyl)phenyl phosphonate

49 di-(p-t-butyl phenyl)phenyl phosphonate

50 di-(o-isopropyl phenyl)phenyl phosphonate

51 di-(p-benzyl phenyl)phenyl phosphonate

52 diphenyl styryl phosphonate

53 diphenyl-1,2-dibrom-2-phenyl ethyl phosphonate

54 diphenyl n-octyl phosphonate

55 diphenyl n-decyl phosphonate

56 di-(p-chlorophenyl)n-butyl phosphonate

57 di-(p-bromophenyl)n-hexyl phosphonate

58 di-(o-isopropyl phenyl)n-octyl phosphonate

59 phenyl n-octyl n-hexylphosphonate

60 phenyl styryl hydrogen phosphonate or its sodium salt

61 phenyl phenyl hydrogen phosphonate

62 phenyl n-octyl phosphonic acid ammonium salt

63 bis-2,3-dibromopropyl-2,3-dibromo propyl phosphonate

64 di-ethyl(2-carbamoyl-N-hydroxymethyl)ethyl phosphonate

65 di-ethyl, di-ethanolamino methyl phosphonate

Non limiting examples of esters based on phosphinic acid are:

66 n-octyl di-styryl phosphinate

67 n-octyl di-(1;2-dibromo-2-phenyl ethyl)phosphinate

68 phenyl di-styryl phosphinate

69 n-decyl di-styryl phosphinate

Non limiting examples of esters based on phosphorous acid are:

70 triphenyl phosphite

71 tri octyl phosphite

72 tri-p-nonyl phenyl phosphite

73 tri-2:3 dibromopropyl phosphite

74 diphenyl hydrogen phosphite

75 dioctyl hydrogen phosphite

Non limiting examples of esters based on phosphonic acid are: ##STR11##

Preferred compounds are the esters of pentavalent phosphorus and, more particularly, triaryl phosphates and tri-halo-alkyl phosphates, for example compounds 1 to 11 and 39 to 42.

The compositions of the invention may contain components a and b in the ratios a:b from 0.1 to 10 to 0.1, but preferably from 1:10 to 10:1, more preferably 1:5 to 5:1, most preferably 1:5 to 3:1.

The amount of (a) together with (b) which can be used per hundred parts of polymer is from 0.1 to 150 parts, preferably 2-100 parts, more preferably 5 to 50 parts, most preferably 5-25 parts by weight. The actual amounts of (a) plus (b) used will vary depending on the particular homopolymer, copolymer or poly blend used and on the type and amount of other ingredients which may be present, such as filler and reinforcing fibres (described hereinafter).

The polymers may be homo or copolymers or polyblends of chlorine containing aliphatic polymers containing at least 5% chlorine, preferable more than 20% chlorine and most preferably more than 40% chlorine. Non-limiting examples of such polymers are polyvinyl chloride, chlorinated polybutene, poly-chloroprene, poly-vinylidene chloride, chlorinated poly -4,4-dimethyl pentene, chlorinated polyethylene, chlorinated polypropylene, also chlorinated polyethylene containing some chlorosulphonyl groups, e.g. those products sold under the trade name "Hypalon". Non-limiting examples of copolymers are vinyl chloride/vinyl acetate, vinyl chloride/vinylidene chloride, vinyl chloride/ethylene, vinyl chloride/propylene, vinyl chloride/acrylic ester copolymers, vinyl chloride/acrylonitrile, chlorinated ethylene/propylene copolymers, chlorinated ethylene/butene copolymers. Poly blends with other polymers may be used, non-limiting examples of which are PVC/rubber blends, in particular blends of PVC with an acrylonitrile based rubber.

Non-limiting examples of mixtures of (a) and (b) which may be used with the polymers are listed below in Table B.

                  Table B                                                          ______________________________________                                         Ex.-  Oligomer                                                                 ample No.      Phosphorus Ester                                                No.   (b)      (a)                                                             ______________________________________                                         1     1        Reofos 95                                                       2     2        Triphenyl phosphate                                             3     3        Tributyl phosphate                                              4     4        Tris (2-chloroethyl) phosphate                                  5     5        Diphenyl 2-chloroethyl phosphate                                6     11       Phenyl bis (2-chloroethyl) phosphate                            7     7        Cresyl diphenyl phosphate                                       8     8        Diphenyl isodecyl phosphate                                     9     9        Diphenyl octyl phosphate                                        10    9        Tri-octyl phosphate                                             11    3        Reofos 95/tris (2-chloroethyl) phosphate                        12    4        Reofos 95/diphenyl decyl phosphate                              13    5        Reofos 95/diphenyl octyl phosphate                              14    7        Diphenyl decyl phosphate/tris (2-chloroethyl)                                  phosphate                                                       15    11       Diphenyl octyl phosphatic/tris (2-chloroethyl)                                 phosphate                                                       16    5        Diphenyl octyl phosphate/tris (2,3-dibromo-                                    propyl) phosphate                                               17    11       Reofos 50/diphenyl decyl phosphate                              18    11       Reofos 95/diphenyl decyl phosphate                              ______________________________________                                    

Compounds of type (b) may optionally be mixed with other non-deactivated aromatic compounds containing vacant positions on an aromatic ring, such as compounds of the formula ACH₂ X where A and X are as defined above. In some cases further enhancement of fire retardance may be obtained thereby. Non-limiting examples of such compounds are:

4,4¹ -di-acetoxy diphenyl methane

4,4¹ -di-methoxy diphenyl methane

2,2-bis-(p-acetoxyphenyl)-propane

2,2-bis-(p-methoxyphenyl)-propane

1,5-di-acetoxy naphthalene

1,5-di-methoxy naphthalene

1-acetoxy-4-phenyl benzene

1-acetoxy-2-phenyl benzene

1-hydroxymethyl naphthalene

1-hydroxymethyl-4-phenyl benzene

diphenyl ether

biphenyl

terphenyl

polybenzyl

Novolaks

polyphenyl ethers

4-hydroxymethyl biphenyl

4-hydroxymethyl diphenyl ether

4-methoxymethyl diphenyl ether

4-acetoxymethyl diphenyl ether

1-hydroxymethyl-2-phenyl benzene

1,5-hydroxymethyl naphthalene mono-methyl mono-hydroxymethyl naphthalenes mono-hydroxymethyl phenanthrene

Mixtures of phosphorus esters can be used, if desired, as can mixtures of compounds of formula I.

The compositions of the invention may also contain other ingredients. For example, they may contain heat stabilisers, light stabilisers, antioxidants, fillers, pigments, lubricants, blowing agents, fungicides, Friedel Crafts catalysts or precursors thereof, extenders, other processing aids and other fire retardant additives, and smoke suppressants. Suitable antioxidants include the sterically hindered phenol compounds for example: 2,2'-thio-bis-(4-methyl-6-tert. butyl-phenol), 4,4'-thio-bis-(3-methyl-6-tert. butylphenol), 2,2'-methylene-bis(4-methyl-6-tert. butylphenol), 2,2'-bis(4,4'-phenylol) propane, 2,2'-methylene-bis-(4-ethyl-6-tert. butylphenol), 4,4'-methylene-bis-(2-methyl-6-tert. butyl-phenol), 4,4'-butylidene-bis-(3-methyl-6-tert. butylphenol), 2,2'-methylene-bis[4-methyl-6-(α-methyl-cyclohexyl)-phenol], 2,6-di(2-hydroxy-3-tert. butyl-5-methylbenzyl) 4-methyl-phenol, 2,6-di-tert.butyl-4-methylphenol, 1,1,3-tris-(2-methyl-4-hydroxy-5-tert.butyl-phenyl)-butane, 1,3,5-trimethyl-2,4,6-tri(3,5-di-tert.butyl-4-hydroxy-benzyl)-benzene, esters of β-4-hydroxy-3,5-di-tert.butylphenylpropionic acid with monohydric or polyhydric alcohols, such as methanol, ethanol, octadecanol, hexanediol, noncanediol, thiodiethylene glycol, trimethylolethane or pentaerythritol, 2,4-bis-octylmercapto-6-(4-hydroxy-3,5-di-tert.butylanilino)-s-triazine, 2,4-bis-(4-hydroxy-3,5-di-tert.butylphenoxy)6-octylmercapto-s-triazine, 1,1-bis(4-hydroxy-2-methyl-5-tert.butylphenyl)-3-dodecyl-mercapto-butane, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis(4-methyl-6-t-butylphenol),4-hydroxy-3,5-di-tert.butylbenzyl-phosphonic acid esters, such as the dimethyl, diethyl or dioctadecyl ester, (3-methyl-4-hydroxy-5-tert.butyl benzyl)-malonic acid dioctadecyl ester, s-(3,5-dimethyl-4-hydroxyphenyl)-thioglycollic acid octadecyl ester, and esters of bis-(3,5-di-tert.butyl-4-hydroxybenzyl)-malonic acid, such as the didodecyl ester, the dioctadecyl ester and 2-dodecylmercaptoethyl ester.

Suitable light stabilisers and uv absorbers include: sterically hindered cyclic amines of the formula II ##STR12## and salts thereof in which q is 1 or 2, X represents an organic grouping which complements the nitrogen-containing ring to give a 5-membered, 6-membered or 7-membered ring, R₁ and R₂ represent methyl or together represent --(CH₂)₅ --, R₃ represents methyl, R₄ represents alkyl with 1-5 carbon atoms or together with R₃ represents the radicals --(CH₂)₄ --, --(CH₂)₅ --, --CH₂ -C(CH₃)₂ --NH-C(CH₃)₂ -CH₂ -- or --CH₂ -C(CH₃)₂ --N(O.sup..)--C(CH₃)₂ -CH₂ -- and, if q is 1, Y denotes hydrogen, --O.sup.., hydroxyl, alkyl, substituted alkyl, alkenyl, alkynyl, aralkyl, substituted aralkyl or acyl or, if q is 2, Y denotes alkylene, alkenylene, alkynylene, cycloalkylene or aralkylene.

Examples of sterically hindered cyclic amines of formula II are 4-benzoyloxy-, 2,2,6,6-tetramethylpiperidine; 4-capryloyloxy-2,2,6,6-tetramethylpiperidine; 4-stearoyloxy-2,2,6,6-tetramethylpiperidine; bis-(2,2,6,6-tetramethyl-4-piperidyl)-sebacate; bis-(2,2,6,6-tetramethyl-4-piperidyl)-dodecanedioate and bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-sebacate.

2-(2'-Hydroxyphenyl)-benztriazoles, such as for example, the 5'-methyl-, 3',5'-di-tert.butyl-, 5'-tert.butyl-, 5'-(1,1,3,3-tetramethylbutyl)-, 5-chloro-3',5'-di-tert.butyl-, 5-chloro-3'-tert.butyl-5'-methyl-, 3'-sec.butyl-5'-tert.-butyl-, 3'-α-methylbenzyl-5'-methyl-, 3'-α-methylbenzyl-5'-methyl-5-chloro-, 4'-hydroxy-, 4'-methoxy-, 4'-octoxy-, 3',5'-di-tert.amyl-, 3'-methyl-5'-carbomethoxyethyl- and 5-chloro-3',5'-di-tert.-amyl-dervative.

2,4-Bis-(2'-hydroxyphenyl)-6-alkyl-s-triazines, such as for example, the 6-ethyl-, 6-heptadecyl- or 6-undecyl-derivative.

2-Hydroxy-benzophenones, such as, for example, the 4-hydroxy-, 4-methoxy-, 4-octoxy, 4-decyloxy, 4-dodecyloxy-, 4-benzyloxy-, 4,2',4'-trihydroxy- or 2'-hydroxy-4,4'-dimethoxy-derivative.

1,3-Bis-(2'-hydroxybenzoyl)-benzenes, such as, for example, 1,3-bis-(2'-hydroxy-4'-hexyloxy-benzoyl)-benzene, 1,3-bis-(2'-hydroxy-4'-octyloxy-benzoyl)-benzene and 1,3-bis-(2'-hydroxy-4'-dodecyloxy-benzoyl)-benzene.

Esters of optionally substituted benzoic acids, such as, for example, phenyl salicylate, octylphenyl salicylate dibenzoylresorcinol, bis-(4-tert.-butylbenzoyl)-resorcinol, benzoylresorcinol and 3,5-di-tert.-butyl-4-hydroxybenzoic acid 2-di-tert.-butyl-phenyl ester or octadecyl ester or 2-methyl-4,6-tert.butyl-phenyl ester.

Acrylates, such as, for example, α-cyano-β,β-diphenylacrylic acid ethyl ester of isooctyl ester, α-carbomethoxycinnamic acid methyl ester, α-cyano-β-methyl-p-methoxy-cinnamic acid methyl ester or butyl ester and N-(β-carbomethoxy-vinyl)-2-methyl-indoline.

Oxalic acid diamides, such as, for example, 4,4'-di-octyloxy-oxanilide, 2,2'-di-octyloxy-5,5'-di-tert.-butyl-oxanilide, 2,2'-di-dodecyloxy-5,5'-di-tert.butyl-oxanilide, 2-ethoxy-2'-ethyl-oxanilide, N,N'-bis-(3-dimethylaminopropyl)-oxalamide, 2-ethoxy-5-tert.butyl-2'-ethyl-oxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert.butyl-oxanilide and mixtures of ortho- and para-methoxy- as well as of o- and p-ethoxy-disubstituted oxanilides.

Nickel compounds, such as, for example, nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)-phenol], such as the 1:1 or 1:2 complex, optionally with additional ligands, nickel complexes of bis-[2-hydroxy-4-(1,1,3,3-tetramethylbutyl)-phenyl]-sulphone, such as the 2:1 complex, optionally with additional ligands such as 2-ethyl-caproic acid, nickel dibutyldithiocarbamate, nickel salts of 4-hydroxy-3,5-di-tert, butylbenzyl-phosphonic acid monoalkyl esters, such as the methyl, ethyl or butyl ester, nickel complexes of ketoximes such as 2-hydroxy-4-methyl-phenyl-undecylketonoxime and nickel 3,5-di-tert.butyl-4-hydroxy-benzoate.

The compositions may for example contain, as stabilisers:

tribasic lead sulphate

basic lead carbonate

basic lead phosphite

lead stearate

basic lead stearate

cadmium laurate

cadmium stearate

cadmium 2-ethyl hexoate

cadmium benzoate

barium laurate

barium stearate

barium phenate

barium alkyl phenates

calcium laurate

calcium stearate

zinc stearate

zinc laurate

zinc 2-ethyl hexoate or other metal salts of branched chain fatty acids

dibutyl tin dilaurate

dibutyl tin thio diglycolate

dibutyl tin thio carboxylate esters

dibutyl tin maleate

other alkyl tin based stabilisers

alkylβamino crotonates and αbis crotonates

thio alkylβamino crotonates and αbis crotonates

α-phenyl indole

epoxidised soya bean oil (for example, the product sold under the Trade Name Reoplas 39)

other epoxy aliphatic or aromatic esters

glycidyl ethers

These stabilisers may be used alone or in any combination. While not essential, where feasible, lowered levels of stabiliser have been found to further increase the flame retardance of the compositions described.

Preferred heat stabilisers are the organotin stabilisers, e.g. dibutyl tin maleate and epoxide stabilisers, e.g. epoxidised soya bean oil (such as that sold under the Trade Name Reoplas 39).

They may also be used with other stabilising and lubricating components, such as:

pentaerythritol

triphenyl phosphite

decyl diphenyl phosphite

didecyl phenyl phosphite

trinonyl phenyl phosphite

stearic acid

hydroxy stearic acid

"Low⃡ molecular weight polyethylene wax

paraffin wax

oxidised paraffin wax

fatty alcohols

esters of straight chain fatty alcohols and straight chain

fatty acids (in which the acids or alcohols are natural or

synthetic)

monoesters of glycols and straight chain fatty acids

methylene bis stearamide

Suitable pigments include organic and inorganic pigments or mixtures thereof. If an organic pigment is used it may be, for example, a phthalocyanine which may be a metal phthalocyanine such as copper phthalocyanine, a metal free phthalocyanine or a chlorinated metal or metal free phthalocyanine, for example a chloromethylated phthalocyanine. Other organic pigments include azo pigments (monoazo or diazo) azo metal salts, anthraquinone and metal complexes. If an inorganic pigment is used it may be, for example, titanium dioxide, carbon black or iron oxide.

The addition of Friedel Crafts catalysts to the composition can in some cases give a marked increased in fire retardance. This effect is particularly observed with aromatic chloromethyl additives.

Suitable Friedel Crafts catalysts either Bronsted or Lewis acids include aluminium chloride, zinc chloride, ferric chloride, magnesium chloride, stannous chloride, stannic chloride, butyl tin trichloride, phosphoric acid, p-toluene sulphonic acid. In addition a latent catalyst may be used, e.g. one which is converted to a Friedel Crafts catalyst by heat or by released hydrogen chloride on thermal decomposition of the vinyl chloride polymer. Such latent catalysts include zinc carbonate, stannous octoate, stannous oxalate and tri-alkyl phosphates.

Suitable fillers include asbestos, glass fibres, kaolin and talc.

Suitable secondary plasticisers or extenders are chlorinated paraffin sold under the trade name Cereclor, styrene resin sold under the trade name Dow Resin 276-V2 and hydrocarbon derivatives sold under the trade name Iranolin PDL18.

Other conventional fire retardant additives may be present, such as antimony oxide.

Examples of smoke suppressants which may be present include ferrocene, aluminium hydrate and tetraphenyl lead.

Mixtures of the phosphorus acid esters can be used, if desired, together with one or more known phosphorus-free plasticisers, e.g. as mixtures of phosphate and phthalate esters or mixtures of phosphate and adipate esters.

However, preferably the phosphorus acid ester is present in a concentration of at least 50%, most preferably in a concentration of 75% in such mixtures. However, where certain haloalkyl phosphates are used alone or in mixtures with aryl phosphates, satisfactory results can be obtained with up to 90% phosphorus-free plasticiser.

Non limiting examples of phosphorus-free plasticisers which can be used in conjunction with compositions described in the invention are:

di(butoxy ethyl) adipate

di-2-ethylhexyl adipate

Linevol 7 9 adipate

di-isooctyl adipate

di-capryl adipate

di-nonyl adipate

isooctyl, isodecyl adipate

Linevol 9 11 adipate

di-isodecyl adipate

poly (butylene adipate)

di-2-ethylbutyl azelate

di-2-ethylhexyl azelate

bis (dimethyl benzyl)ether

o-nitro diphenyl

polyethylene glycol monophenyl ether

toluene N-ethyl sulphonamide

di(α-phenylethyl)ether

di-capryl azelate

di-n-butyl sebacate

di-alphol-7,9-sebacate

di-iso-octyl sebacate

di-capryl sebacate

di-nonyl sebacate

tri-ethylene glycol di-caprylate

iso-octyl iso-decyl esters of AGS acids

iso-octyl epoxy stearate

nonyl esters of AGS acids

iso-octyl esters of AGS acids

iso-decyl esters of AGS acids

n-heptyl esters of AGS acids

di-iso-decyl succinate

butoxethyl diglycol carbonate

tributyl citrate

acetyl triethyl citrate

acetyl tributyl citrate

acetyl tri(2-ethylhexyl) citrate

2,2(2-ethylhexamide) diethyl di(2-ethylhexoate)

polyethylene glycol di-2-ethylhexoate

2-butoxyethyl oleate

tetrahydrofuryl oleate

di-n-butyl phthalate

di-isobutyl phthalate

di-2-ethyl butyl phthalate

iso butyl nonyl phthalate

di-n-heptyl phthalate

di-2-ethyl hexyl phthalate

di-isooctyl phthalate

di-capryl phthalate

di-n-octyl phthalate

isooctyl isodecyl phthalate

"Linevol" 7 9 phthalate

"Linevol 9 11" phthalate

("Linevol" 7 9 and "Linevol" 9 11 are mixtures of predominantly straight chain aliphatic alcohols containing 7 to 9, and 9 to 11 carbon atoms respectively).

di-2-phenylethyl phthalate

di-tri-decyl phthalate

butyl benzyl phthalate

di-methyl glycol phthalate

tri-isooctyl tri mellitate

butyl phthalyl butyl glycolate

tri-cotyl tri mellitate

di-benzyl phthalate

di-phenyl phthalate

di-2-phenoxyethyl phthalate

tri-phenyl tri mellitate

tetra-phenyl pyromellitate

ethyl benzoyl benzoate

di-propylene glycol dibenzoate

benzyl benzoate

diphenoxyethyl diglycolate

bis(phenyl polyethylene glycol)diglycolate

phenoxyethyl laurate

phenoxyethyl oleate

di-phenyl adipate

di-benzyl adipate

benzyl octyl adipate

octyl phenyl adipate

butyl benzyl adipate

dibutoxyethyl sebacate

di (2-ethylhexyl) sebacate

2-butoxyethyl stearate

acetophenone

epoxy plasticisers, such as

epoxidised fatty glycerides

polymeric epoxy plasticisers

epoxidised ethylhexyl oleate

aliphatic nitriles

di-benzyl sebacate

di-(2-phenoxy ethyl) adipate

butyl benzyl sebacate

n-octyl n-decyl phthalate/succinate

phenyl diglycol carbonate

cresyl diglycol carbonate

bis-(dimethyl benzyl) carbonate

di-ethylene glycol dibenzoate

dipropylene glycol dibenzoate

tribenzylcitrate

alkyl-sulphonate esters of phenols, e.g. products sold under the trade name "Mesamoll".

o-cresyl-p-toluene sulphonate

In addition, various polyesters may be used, for example, polyesters derived from adipic acid and a glycol end-stopped with an alcohol or mono-basic acid; polyesters derived from AGS acids (a commercial mixture of adipic, glutaric and succinic acids) and a glycol end-stopped with an alcohol or mono-basic acid; polyesters derived from phthalic anhydride and one or more glycols, optionally end stopped by an alcohol or mono-basic acid; polyesters derived from a mixed phthalic/adipic acid and a glycol, optionally end stopped by an alcohol or mono-basic acid; polyesters derived from mixed phthalic/AGS acids and a glycol, optionally end stopped by an alcohol or mono-basic acid. In addition, polyesters of these types modifed by a lactone, e.g. ε-caprolactone may be used.

Examples of mixtures of esters of phosphorus acids with other plasticisers, stabilisers, fillers, etc. which can be used with the oligomers include the following listed in Table C.

                  Table C                                                          ______________________________________                                         Example                                                                               Oligomer Phosphorus ester, plasticisers and                             No.    No.      extenders                                                      ______________________________________                                         1      11       Reofos 95 + dioctyl phthalate                                  2      2        Reofos 95 + dioctyl adipate                                    3      5        Diphenyl decyl phosphate + dioctyl                                             phthalate                                                      4      11       Diphenyl decyl phosphate + dioctyl                                             adipate                                                        5      6        Diphenyl octyl phosphate + dioctyl                                             phthalate                                                      6      11       Diphenyl octyl phosphate + dioctyl                                             adipate                                                        7      5        Reofos 50 + dioctyl phthalate +                                                chlorinated hydrocarbons or hydro-                                             carbon extenders                                               8      11       Diphenyl decyl phosphate + dioctyl                                             phthalate + chlorinated hydrocarbon                                            or hydrocarbon extenders                                       9      5        Diphenyl decyl phosphate + tris                                                (2-chloroethyl) phosphate + chlor-                                             inated hydrocarbon or hydrocarbon                                              extenders                                                      10     6        Diphenyl octyl phosphate + tris                                                (2-chloroethyl)phosphate + dioctyl                                             phthalate                                                      11     11       Diphenyl octyl phosphate + polyester                                           plasticisers + chlorinated hydro-                                              carbon extenders                                               12     5        Diphenyl decyl phosphate + polyester                                           plasticisers + chlorinated hydro-                                              carbon extenders                                               13     11       Diphenyl decyl phosphate + polyester                                           plasticisers + phthalate plasticisers                          14     11       Phosphonates + phthalates                                      15     11       Alkyl aryl phosphates + phthalates                             ______________________________________                                    

In addition, any of the above combination or any sole phosphorus acid ester or mixture of phosphorus acid esters or combinations thereof with or without other optionally phosphorus-free plasticisers can be used with silica, barium metaborate, Sb₂ O₃ and diluted forms thereof, Al(OH)₃ or "alumina trihydrate", carbon, calcium carbonates, clay fillers and stearic acid coated calcium carbonate taken singly or in any combination.

When combinations of esters or plasticisers are used, the proportions can be varied over a wide range and will normally depend on the end use to which the polymer is to be put and, for example, whether a black or clear polymer is desired. Such variations will be readily apparent to those skilled in the art.

The oligomers of the present invention can be prepared by conventional methods; examples of which are:

a the reaction of naphthalene with formaldehyde in the presence of an acid catalyst to produce oligomers with structures having predominently methylene (--CH₂ --) and acetal (--(CH₂ O)_(n) --CH₂ --) links with some di-methylene ether links (--CH₂ --O--CH₂ --), or

b by the chloromethylation of naphthalene to produce mixtures of mono, di and higher chloromethyl naphthalenes which are then hydrolysed and oligomerised to produce oligomers having predominently di-methylene ether (--CH₂ --O--CH₂ --) and methylene (--CH₂ --) links, or

c by reacting a chloromethylated aromatic compound, e.g. benzyl chloride, with formaldehyde or a precurser thereof, such as trioxymethylene and an acid catalyst to give a chloromethylated diaryl methane, e.g. bis-chloromethyl di-phenylmethane. The latter are hydrolysed and oligomerised with aqueous sodium carbonate or are converted, via the acetoxymethyl compounds, into the hydroxymethyl derivatives and then oligomerised with an acid catalyst.

General methods of preparation of the oligomers used in the Examples below are as follows:

Chloromethylation (see Table 1)

This reaction is carried out in an efficient fume cupboard because of the possible formation of bis-chloromethyl ether in the vapour phase above the reaction mixture.

A 5 liter four-neck round bottom flask is fitted with a stirrer, thermometer, gas inlet tube and a reflux condenser. The off-gas from the reaction is conveyed to a scrubber in which 2 liters of water is continuously circulated and maintained alkaline to phenolphthalein by addition of 46% w/w aqueous sodium hydroxide as required.

The reactants specified in Table 1 are charged to the flask and heated and stirred at 90° C. for the time required to achieve the desired level of chloromethylation. During this period, hydrogen chloride gas is passed into the reaction mixture at the rate indicated in Table 1. The progress of chloromethylation is monitored by NMR analysis.

Passage of hydrogen chloride and stirring is stopped and the reaction mixture allowed to cool to room temperature. The aqueous layer is removed and the crude product washed with two 1000 g. portions of cold water. The crude product is an off-white solid.

Hydrolysis of chloromethylated naphthalene using aqueous sodium carbonate (see Table 2)

To the crude chloromethylated naphthalene is added the amount of anhydrous sodium carbonate specified in Table 2 and 786 g. of water for every g. mol. of anhydrous sodium carbonate. The reaction mixture is stirred and heated at 100° C. for eight hours.

The amount of sodium hydroxide given in Table 2 is then added as a 46% w/w aqueous solution, and heating and stirring at 100° C. continued for a further six hours. The mixture is allowed to cool and the aqueous phase removed by decantation. The organic phase is washed twice with water at 60° C. and finally dried by heating and stirring for three hours at 110° C. and 20 mm. mercury pressure.

Oligomers derived from hydroxymethyl naphthalenes or hydroxymethyl naphthalene oligomers (Table 3)

The hydroxymethyl compound is heated in toluene (about 13% w/w) with 88% phosphoric acid (1% w/w) as catalyst. The amounts of toluene and phosphoric acid are calculated with respect to the amount of hydroxymethyl compound. The reaction is carried out in a flask fitted with a stirrer, thermometer, and a water separator surmounted by a reflux condenser. The reaction times at 150° C. and the amounts of water removed by the water separator are given in Table 3.

The reaction mixture is allowed to cool, diluted with chloroform, washed twice with water, and the solvent removed by heating in a distillation apparatus under reduced pressure. The product is finally stripped at 110° C. for three hours at 20 mm. mercury pressure.

Conversion of chloromethyl naphthalenes into the corresponding acetoxymethyl derivatives (Table 4)

The reactants given in Table 4 are stirred under reflux at 122° C. for nine hours. After cooling to room temperature the reaction mixture is filtered and the white precipitate washed with hot acetic acid. The filtrate and washings are then stripped under 20 mm. mercury pressure up to a maximum internal temperature of 100° C. The residual crude product is then stirred with dichloromethane at room temperature, filtered, the precipitate washed with dichloromethane and the combined filtrate and washings stripped under a pressure of 20 mm. mercury up to an internal temperature of 100° C. to leave the product as the distillation residue.

Hydrolysis of acetoxymethyl naphthalenes to the corresponding hydroxymethylnaphthalenes (see Table 5)

The hydrolysis is carried out by refluxing the acetoxymethyl naphthalene with its own weight of ethanol in the presence of 20% aqueous sodium hydroxide for four to nine hours. The reaction mixture is then diluted with water and cooled to room temperature. The mixture is extracted with ether, the latter washed several times with water and then dried over sodium sulphate. The ether is removed by distillation and the residual product finally stripped for one hour at 100° C. and 20 mm. mercury pressure.

1,5 Bis-acetoxymethyl naphthalene was purified using the conditions shown in Table 6. In Table 7 oligomers prepared from various aromatic compounds are listed.

                                      Table 1                                      __________________________________________________________________________     Chloromethylation of naphthalene                                               REACTANTS (mols.)                                                                                     Formaldehyde                                            as 37% aqueous                                                                              Conc. HCl solution          Reaction                                                                            Moles - CH.sub.2 Cl/             Preparation  (HCl gas flow rate                                                                       (p = paraformalde-                                                                               time mole naphthalene                 No.   Naphthalene                                                                           ml/min.)  hyde)      Catalyst                                                                              (hours)                                                                             by H NMR                         __________________________________________________________________________     1     4.0    13.8      18.9       --     12   1.47                                          500-1,000                                                         2     4.0    13.8      16.0p      --     --   --                                            (340)     +5.5p             4    1.1                                                     +4.17p            10   1.35                                                    --                15   1.54                             3     4.0    13.8      18.9       --     --   --                                            (320)     +9.0p             12   1.22                                                    --                16   1.49                             4     4.0    13.8      18.9       ZnCl.sub.2                                                                            --   --                                            (230)     --         (0.19) 6    1.02                                                    --                12   1.4                                                     18.9              17   --                                                      (aq. layer replaced)                                                                             22   1.88                             5     4.0    13.9      18.9       ZnCl.sub.2                                                                            8    1.26                                          (500)                (0.04)                                       6     4.0    13.8      18.9       --     12   1.5                                           (450)                                                             7     4.0    13.8      18.9       --     --   --                                                      --                7.5  1.2                                                     18.9              12.0 1.3                                                     (aq. layer replaced)                                                           --                16.0 1.6                                                     18.9              17.0 --                                                      --                22.5 1.7                                                     10.0p             27.0 1.9                                                     --                30.0 2.0                              8     4.0    13.8      16.0p      ZnCl.sub.2                                                                            --   --                                            (500)     +7.2p      (0.19) 8    1.38                             9     4.0    13.8      16.0p      ZnCl.sub.2                                                                            5    1.38                                          (500)     +8.33p     +0.76  10   1.6                                                     +8.13p     +CH.sub.3 CO.sub.2 H                                                                  15   1.93                             __________________________________________________________________________

                                      Table 2                                      __________________________________________________________________________     Hydrolysis of Chloromethylated Naphthalenes                                    using aqueous sodium carbonate                                                 (reflux 100° C. for 14 hours)                                               Chloro-                     % Mono-                                                                             % Bis                                         methylated                  hydroxy                                                                             hydroxy                                   Prep-                                                                              naph-   REACTANTS                                                                               Mole       methyl                                                                              methyl                                    aration                                                                            alene(moles)                                                                           (MOLES)  --CH.sub.2 OH/                                                                       %    naph-                                                                               naph-                                                                               M                                    No. Preparation No.                                                                        Na.sub.2 CO.sub.3                                                                   NaOH                                                                               mole  Oxygen                                                                              thalene                                                                             thalene                                                                             Weight                                                                             Yield %                          __________________________________________________________________________     10  1       2.63 0.90                                                                               1.12  8.2  2.0  9.0  440 81                                   (3.42)                                    viscous                                                                        liquid                           11  2       0.77 0.26                                                                               1.36  --   8.0  2.0  325 78                                   (1.0)                                     viscous                                                                        liquid                           12  3       3.19 1.05                                                                               1.04  9.9  15.0 5.0  340 73                                   (4.0)                                     viscous                                                                        liquid                           13  4       3.57 1.35                                                                               1.38  13.1 15.0 15.0 380 73 very                              (3.85)                                    viscous                                                                        liquid                           14  5       3.17 1.08                                                                               1.03  2.0  30.0 3.0  280 77                                   (3.84)                                    viscous                                                                        liquid                           15  8       3.09 1.62                                                                               0.82  8.9  10.0 2.5  385 81                                   (4.0)                                     viscous                                                                        liquid                           __________________________________________________________________________

                                      Table 3                                      __________________________________________________________________________     Oligomers derived from                                                         hydroxymethyl naphthalenes or oligomers                                        (1% of H.sub.3 PO.sub.4 /toluene/150° C.)                                          Amount H.sub.2 O                                                        Hydroxy-                                                                              removed                     % mono-                                                                             % bis-                                 methyl (mole/                      hydroxy-                                                                            hydroxy-                           Prep-                                                                              naphthalene                                                                           mole of            Mole     methyl                                                                              methyl                             aration                                                                            Preparation                                                                           starting                                                                              Reaction                                                                              Yield                                                                               CH.sub.2 OH/                                                                        %   naph-                                                                               naph-                                                                               M                             No. No.    material)                                                                             time (hour)                                                                           %    mole oxygen                                                                             thalene                                                                             thalene                                                                             Weight                        __________________________________________________________________________     16  27     0.61   1.5    94                                                                             hard                                                                           plastic                                                                             0.54 --  5.0  <1.0 530                           17  15     0.47   4.5    84   0.39 7.1 6.0  0.2  550                                                    brittle                                                                        solid                                                 18  28     0.53   4.0    94   --   --  15.0 1.0  530                                                    very                                                                           viscous                                                                        liquid                                                19  11     0.77   0.75   78                                                                             powder                                                                              0.11 7.0 0    <1.0 760                           20  29     0.49   9      93   2.05 16.9                                                                               0    35   460                                             (150°-200° C.)                                                          yellow                                                                  (3% H.sub.3 PO.sub.4)                                                                 powder                                                21  14     1.24   0.75   94   0.34 1.2 0.5  1.0  600                                                    yellow                                                                         powder                                                __________________________________________________________________________

                                      Table 4                                      __________________________________________________________________________     Conversion of chloromethyl naphthalenes into the corresponding                 acetoxymethyl derivatives                                                          Chloro-             Reaction                                               Prep-                                                                              methylated          time                                                   aration                                                                            naphthalene                                                                            REACTANTS (moles)                                                                          at 122° C.                                      No. Preparation No.                                                                        CH.sub.3 CO.sub.2 K                                                                  CH.sub.3 CO.sub.2 H                                                                  (hours)                                                                              Product                                          __________________________________________________________________________     22  7       10.0  75.0  9     Bis-acetoxymethyl naphthalene                        (4.0)                     together with naphthalene                                                      oligomers.                                                                     Brown viscous liquid                             23  2       8.3   50.0  9     Equimolar mixture of 1 and                           (3.33)                    1,5-bis-acetoxymethyl naphthalene                24  6       9.14  55.3  9     Equimolar mixture of 1 and                           (3.64)                    1,5-bis-acetoxymethyl naphthalene                25  9       7.53  37.5  9     90% 1,5-bis acetoxymethyl                            (3.36)                    naphthalene and 10% 1-acetoxy-                                                 methyl napthalene                                __________________________________________________________________________

                                      Table 5                                      __________________________________________________________________________     Hydrolysis of acetoxymethyl-naphthalene derivatives to the                     corresponding hydroxymethylnaphthalenes                                        (reflux 4-9 hr. in aqueous ethanol with 20% NaOH)                                   Acetoxymethyl                                                                  naphthalene                                                               Prepar-                                                                             (moles) Sodium                                                            ation                                                                               Preparation                                                                            hydroxide                                                         No.  No.     (moles)                                                                              Yield %                                                                             Product                                                __________________________________________________________________________     26   22      1.31  88   Brown solid; mainly bis-hydroxymethyl                                          naphthalenes                                                (0.37)             + minor amounts of oligomers                           27   23      7.54  94   Semi-solid; equimolecular mixture of mono- and              (2.11)             bis-hydroxymethyl naphthalenes                         28   24      5.45  86   Waxy solid; equimolar mixture of mono- and bis-             (1.53)             hydroxymethyl naphthalenes                             29   30      7.83  88   Brown solid; melting point 107°-117°                              C.; bis-hydroxy-                                           (2.2)              methyl naphthalenes                                    __________________________________________________________________________

                                      Table 6                                      __________________________________________________________________________     Purification of 1,5-bis acetoxymethyl naphthalene                              (removal of 1-acetoxymethyl naphthalene)                                       Composition VACUUM STRIPPING                                                   of starting AT                                                                 material    1.5 mm. MERCURY PRESSURE                                                (Wt. taken,            % bis-     Weight of                               Prepar-                                                                             g.)                    AcOCH.sub.2 -                                                                             product                                 ation                                                                               Preparation                                                                           fore-run                                                                            boiling    naph- Weight                                                                              g.    T.L.C.                            No.  No.    fraction                                                                            range (°C.)                                                                   % mono-                                                                             thalene                                                                              (g)  (% yield)                                                                            analysis                          __________________________________________________________________________     30   25     1    150-156                                                                              93   7.4   21   597   Mainly bis-                                                                    AcOCH.sub.2                                   2    156-160                                                                              88   12    31.9 (86)  naphthalene                                                                    with traces of                         90% 1,5-                                                                              3    160-170                                                                              73   27    15.3       mono-AcOCH.sub.2 -                     and                                     naphthalene                            10%    4    170-200                                                                              7.2  93    21.5       and oligomers                          1-acetoxy                                                                      methyl 5    200   1.6  98    3.85                                              naph-                        -93.55                                            thalene                                                                        (691)                                                                     __________________________________________________________________________

                                      Table 7                                      __________________________________________________________________________     Oligomers from various aromatic compounds                                      REACTANTS (MOLS)                                                                No. arationPrep-                                                                   ##STR13##          hydeformalde-Para-                                                                  usedH.sub.2 SO.sub.4aqueous%                                                         (hour)timetionReac-                                                                (g)Yield                                                                           weightecularMole-                                                                  oxygen%                         __________________________________________________________________________     31  0.9                3.0  40(1.0)                                                                              3.0 96.0                                                                               400 5.9                              32  0.5       C.sub.6 H.sub.5 . OC.sub.6 H.sub.5                                             0.5      3.0  40(1.0)                                                                              3.0 151 650 15.8                             33  --                                                                                        ##STR14##          0.75                                                                               72% of theory                                                                      440 17.0                                           with 1% NH.sub.2 SO.sub.3 H catalyst at 160° C.           34  0.5       toluene  3.0  40(1.0)                                                                              6.0 85.8                                                                               550 7.6                                            0.5                                                              35  1.0       CH.sub.3 CO.sub.2 H                                                            1.0      3.0  45(1.0)                                                                              4.0 150 500 6.3                              36  0.9       C.sub.6 H.sub.5 . O . C.sub.6 H.sub.5                                                   3.0  40(1.0)                                                                              3.0 107 470 10.9                                           0.1                                                              37  1.0       CH.sub.3 OH                                                                             3.0  45(1.0)                                                                              6.0 130 410 10.1                                           1.0                                                              38  --        C.sub.6 H.sub.5 . O . C.sub.6 H.sub.5                                                   3.0  40(0.75)                                                                             4.5 124 890 19.6                                           1.0                                                              __________________________________________________________________________

Preparation of the naphthalene oligomers used in the formulations of Table 10 is exemplified by the following method.

A mixture of paraformaldehyde (114 g.) water (115 g.) and concentrated sulphuric acid (85 g.) was heated to 95° C. Naphthalene (120 g.) was added to the reaction mixture over 20 minutes at 90°-95° C. The mixture was then refluxed for 2 hours at 105° C. On cooling, the aqueous layer was decanted off and the product washed with dilute sodium carbonate solution to remove acid. Unreacted naphthalene was removed by steam distillation and the organic product was dissolved in toluene (300 mls.) separated, and dried on a rotary evaporator under water and then oil pump vacuum at 90° C. The product was a very viscous pale yellow liquid.

Yield=120 g.

Analytical details of products are listed in Table 8.

                  Table 8                                                          ______________________________________                                         Oligomer No.                                                                               Molecular Weight                                                                               % Oxygen                                           ______________________________________                                         39          425             10.0                                               40          465             10.0                                               41          510             8.5                                                42          550             9.5                                                ______________________________________                                    

The invention is illustrated by the following Examples.

PVC compositions were made up using several different flame retardant compositions as set out in the Tables 8 to 13, the amounts of constituents being given in parts by weight. The compositions contained 100 parts PVC, and were compounded on a laboratory two roll mill for 15 minutes at 165° C. and then passed into sheets 6 inches×6 inches×0.100 inch in a heated press at 178° C. The sheets were then aged for 5 days at a constant temperature of 23° C. After this time the IRHD (International Rubber Hardness Degrees BS 903) and Oxygen Index (OI ASTM 2863) of the sheets were measured.

In order that comparisons can be made with compositions not containing compound (b) comparative examples are included.

EXAMPLES 1-8

By comparing Examples 1 to 8 with comparative Example A in Table 9, it can be seen that a great improvement in flame resistance as measured by Oxygen Index can be achieved. Also, Examples 1, 2, 5 and 6 have superior flexibility compared to comparative Example A.

                                      Table 9                                      __________________________________________________________________________     Polyvinyl Chloride                                                                 Naph-    Parts                                                                 thalene  of                                                                Ex- Oligomer naph-                     TEST                                    ample                                                                              Preparation                                                                          M. thalene                                                                             Phosphorus Ester     RESULTS                                 No. No.   Wt.                                                                               oligomer                                                                            (parts)  Stabiliser (parts)                                                                         O.I.                                                                              IRHD                                 __________________________________________________________________________     1   13    380                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    67.2                                                                              75.0                                 A   --    -- --   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    33.0                                                                              91                                   2   20    600                                                                               10   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    53.5                                                                              77.0                                     21    700                                                                               10                                                                3   14    280                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    51.3                                                                              --                                   4   14    600                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    60.0                                                                              --                                   5   11    325                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    74.5                                                                              80.5                                 6   16    530                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    74.5                                                                              86.0                                 7   19    650                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    69.4                                                                              90.0                                 8   26       20   Reofos 95 (50)                                                                          Dibutyl tin maleate (2)                                                                    59.5                                                                              --                                   __________________________________________________________________________

EXAMPLES 9 TO 15

Examples 9 to 15 in Table 10 show the effect of using different phosphorus esters on the flame retardance of PVC compositions. Haloalkyl phosphates are particularly effective, in particular those used in Examples 10 and 12.

                                      Table 10                                     __________________________________________________________________________     Polyvinyl Chloride                                                                 Naphthalene                                                                               Parts of                                                        Ex- Oligomer   naph-                                   TEST                    ample                                                                              Preparation                                                                            M. thalene                                                                              Phosphorus Ester           Stabiliser                                                                            RESULTS                 No. No.     Wt.                                                                               oligomer                                                                             (parts)                    (parts)                                                                               O.I.                                                                               IRHD                __________________________________________________________________________      9  17      540                                                                               20                                                                                    ##STR15##                 Dibutyl tin maleate                                                                   56.9                                                                               --                  10  16      530                                                                               20    OP[OCH(CH.sub.2 Cl).sub.2 ].sub.3 (50)                                                                    Epoxidised                                                                            85.0                                                                               77.0                                                                soya bean                                                                      oil                                                                            (Reoplast 39)                                                                  (4)                            11  12      385                                                                               20                                                                                    ##STR16##                 Dibutyl tin maleate                                                                   69.4                                                                               67.5                12  12      385                                                                               20                                                                                    ##STR17##                 Dibutyl tin maleate                                                                   82.5                                                                               81.0                13  12      385                                                                               20                                                                                    ##STR18##                 Epoxidised soya bean oil                                                       (2)    84.3                                                                               --                  14  17      540                                                                               20                                                                                    ##STR19##                 Dibutyl tin maleate                                                                   56.9                                                                               --                  15  10      440                                                                               20                                                                                    ##STR20##                 Dibutyl tin maleate                                                                   64.1                                                                               84.0                __________________________________________________________________________

EXAMPLES 16 TO 19

Table 11 shows the affect of using naphthalene oligomers prepared by the reaction of naphthalene and formaldehyde in the presence of a catalyst. An improvement in flame retardance is shown in all the Examples compared to Example A and in Examples 16 and 17 improved flexibility is also achieved.

                                      Table 11                                     __________________________________________________________________________     Polyvinyl Chloride                                                                 Naphthalene                                                                              Parts of                                                         Ex- Oligomer  naph-                   TEST                                     ample                                                                              Preparation                                                                           M  thalene                                                                             Phosphorus Ester   RESULTS                                  No. No.    Wt.                                                                               oligomer                                                                            (parts)  Stabiliser (parts)                                                                       O.I.                                                                              IRHD                                  __________________________________________________________________________     16  39     425                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate                                                                      36 83                                                                (2)                                                17  40     465                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate                                                                      35.3                                                                              85                                                                (2)                                                18  41     510                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate                                                                      40.6                                                                              --                                                                (2)                                                19  42     550                                                                               20   Reofos 95 (50)                                                                          Dibutyl tin maleate                                                                      41.8                                                                              96                                                                (2)                                                __________________________________________________________________________

EXAMPLES 20 TO 40

The Examples in Table 12 show the effect of using a conventional PVC plasticiser as part of the composition. A particularly effective phosphorous ester is tris(2-chloroethyl)phosphate. Compositions with high Oxygen Index and good flexibility can be achieved using these formulations, e.g. Example Nos. 28, 29, 31, 32, 33, 35, 36, 37 and 40. Such properties cannot be achieved in PVC using current technology, since an increase in flame retardancy leads to a decrease in flexibility.

                                      Table 12.                                    __________________________________________________________________________     Polyvinyl Chloride                                                                 Naph-                                                                          thalene                                                                               Parts                                                                   Oligo- of                                                                      mer    naph-                                                               Ex- Prep-  thalene                        Stabil-       TEST                   ample                                                                              aration                                                                            M. oligo-                                                                             Phosphorus Ester           iser Plasticiser                                                                             RESULTS                No. No. Wt.                                                                               mer (parts)                    (parts)                                                                             (parts)  O.T.                                                                              IRHD                __________________________________________________________________________     20  10     20                                                                                  ##STR21##                 Epoxi- dised soya bean oil                                                          "Linevol" 79                                                                   tri- mellitate (40)                                                                     35.3                                                                              79.0                B   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               27.7                                                                              87.0                                                          dised                                                                               79 tri-                                                                   soya mellitate                                                                 bean (40)                                                                      oil (4)                              21  16  530                                                                               20  Reofos 95 (25)             Dibutyl                                                                             Butyl benzyl                                                                            34.2                                                                              --                                                            tin  phthalate                                                                 maleate                                                                             (25)                                                                      (2)                                  C   --  -- --  "                          Dibutyl                                                                             Butyl benzyl                                                                            30.3                                                             tin  phthalate                                                                 maleate                                                                             (25)                                                                      (2)                                  22  16  530                                                                               20  "                          Dibutyl                                                                             Bis (phenoxy-                                                                           49.9                                                             tin  ethyl)                                                                    maleate                                                                             phthalate (25)                                                            (2)                                  D   --  -- --  "                          Dibutyl                                                                             Bis (phenoxy-                                                                           32.0                                                             tin  ethyl                                                                     maleate                                                                             phthalate (25)                                                            (2)                                  23  16  530                                                                               20  "                          Dibutyl                                                                             "Mesamoll"                                                                              32.9                                                             tin  (Aryl ester                                                               maleate                                                                             of an alkyl                                                               (2)  sulphonic                                                                      acid) (25)                      E   --  -- --  "                          Dibutyl                                                                             "Mesamoll"                                                                              28.3                                                             tin  (Aryl ester                                                               maleate                                                                             of an alkyl                                                               (2)  sulphonic                                                                      acid) (25)                      24  16  530                                                                               20  Tris (2-chloro-ethyl) phosphate (25)                                                                      Epoxi-                                                                              "Mesamoll"                                                                              74.0                                                                              69.5                                                          dised                                                                               (Aryl ester                                                               soya of an alkyl                                                               bean sulphonic                                                                 oil (4)                                                                             acid) (25)                      F   --  -- --  "                          Epoxi-                                                                              "Mesamoll"(Aryl                                                                         30.4                                                                              75.0                                                          dised                                                                               ester of an                                                               soya alkylsulphonic                                                            bean acid) (25)-    oil (4)          25  16  530                                                                               20  "                          Epoxi-                                                                              "Bis (phenoxy-                                                                          77.7                                                                              78.0                                                          dised                                                                               ethyl) phthalate                                                          soya (25)                                                                      bean                                                                           oil (4)                              G   --  -- --  "                          Epoxi-                                                                              Bis (phenoxy-                                                                           35.0                                                                              88.0                                                          dised                                                                               ethyl) phthalate                                                          soya (25)                                                                      bean                                                                           oil (4)                              26  16  530                                                                               20  Tris (2-chloro-ethyl) phosphate (10)                                                                      Epoxi-                                                                              Bis (phenoxy-                                                                           35.2                                                                              86.5                                                          dised                                                                               ethyl) phthalate                                                          soya (40)                                                                      bean                                                                           oil (4)                              H   --  -- --  "                          Epoxi-                                                                              Bis (phenoxy-                                                                           29.9                                                                              89.0                                                          dised                                                                               ethyl) phthalate                                                          soya (40)                                                                      bean                                                                           oil (4)                              27  16  530                                                                               20  Tris (2-chloro-ethyl) phosphate (25)                                                                      Epoxi-                                                                              Butyl benzyl                                                                            59.9                                                                              67.0                                                          dised                                                                               phthalate (25)                                                            soya                                                                           bean                                                                           oil (4)                              I   --  -- --  "                          Epoxi-                                                                              Butyl benzyl                                                                            33.2                                                                              76.0                                                          dised                                                                               phthalate (25)                                                            soya                                                                           bean                                                                           oil (4)                              28  16  530                                                                               20  "                          Epoxi-                                                                              Di-octyl 62.8                                                                              60.5                                                          dised                                                                               phthalate (25)                                                            soya                                                                           bean                                                                           oil (4)                              J   --  -- --  "                          Epoxi-                                                                              Di-octyl 30.3                                                                              75.0                                                          dised                                                                               phthalate (25)                                                            soya                                                                           bean                                                                           oil (4)                              29  16  530                                                                               20  "                          Epoxi-                                                                              Dioctyl  58.9                                                                              65.5                                                          dised                                                                               adipate (25)                                                              soya                                                                           bean                                                                           oil (4)                              K   --  -- --  "                          Epoxi-                                                                              Dioctyl  29.1                                                                              73.5                                                          dised                                                                               adipate (25)                                                              soya                                                                           bean                                                                           oil (4)                              30  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (10)                                                                      Epoxi-                                                                              "Linevol"                                                                               48.4                                                                              67.5                                                          dised                                                                               79 tri-                                                                   soya mellilate (40)                                                            bean                                                                           oil (4)                              L   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               29.0                                                                              76.5                                                          dised                                                                               79 tri-                                                                   soya mellilate (40)                                                            bean                                                                           oil (4)                              31  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (15)                                                                      Epoxi-                                                                              "Linevol"                                                                               62.5                                                                              68.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (35)                                                            bean                                                                           oil (4)                              M   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               29.3                                                                              77.5                                                          dised                                                                               79 tri-                                                                   soya mellilate (35)                                                            bean                                                                           oil (4)                              32  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (20)                                                                      Epoxi-                                                                              "Linevol"                                                                               70.7                                                                              67.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (30)                                                            bean                                                                           oil (4)                              O   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               30.7                                                                              77.5                                                          dised                                                                               79 tri-                                                                   soya mellilate (30)                                                            bean                                                                           oil (4)                              33  10  440                                                                               20  Tris (2-Chloro-ethyl) phosphate (30)                                                                      Epoxi-                                                                              "Linevol"                                                                               75.1                                                                              67.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (20)                                                            bean                                                                           oil (4)                              P   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               33.6                                                                              78.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (20)                                                            bean                                                                           oil (4)                              34  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (25)                                                                      Epoxi-                                                                              "Linevol"                                                                               77.3                                                                              74.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (15)                                                            bean                                                                           oil (4)                              Q   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               34.6                                                                              85.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (15)                                                            bean                                                                           oil (4)                              35  10  440                                                                               20  "                          Epoxi-                                                                              "Linevol"                                                                               75.4                                                                              63.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (35)                                                            bean                                                                           oil (4)                              R   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               31.5                                                                              73.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (35)                                                            bean                                                                           oil (4)                              36  10  440                                                                               20  "                          Epoxi-                                                                              "Linevol"                                                                               74.1                                                                              63.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (45)                                                            bean                                                                           oil (4)                              S   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               28.4                                                                              65.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (45)                                                            bean                                                                           oil (4)                              37  10  440                                                                               20  "                          Epoxi-                                                                              "Linevol"                                                                               69.8                                                                              58.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (55)                                                            bean                                                                           oil (4)                              T   --  -- --  "                          Epoxi-                                                                              "Linevol"                                                                               27.4                                                                              62.0                                                          dised                                                                               79 tri-                                                                   soya mellilate (55)                                                            bean                                                                           oil (4)                              38  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (10)                                                                      Epoxi-                                                                              Dioctyl  37.5                                                                              80.5                                                          dised                                                                               phthalate                                                                 soya (40)                                                                      bean                                                                           oil (4)                              U   --  -- --  "                          Epoxi-                                                                              Dioctyl  25.4                                                                              79.4                                                          dised                                                                               phthalate                                                                 soya (40)                                                                      bean                                                                           oil (4)                              39  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (20)                                                                      Epoxi-                                                                              Dioctyl  52.8                                                                              70.5                                                          dised                                                                               phthalate                                                                 soya (35)                                                                      bean                                                                           oil (4)                              V   --  -- --  Tris (2-chloro-ethyl) phosphate (15)                                                                      Epoxi                                                                               Dioctyl  27.4                                                                              77.5                                                          dised                                                                               phthalate                                                                 soya (35)                                                                      bean                                                                           oil (4)                              40  10  440                                                                               20  Tris (2-chloro-ethyl) phosphate (20)                                                                      Epoxi-                                                                              Dioctyl  61.0                                                                              69.5                                                          dised                                                                               phthalate                                                                 soya (30)                                                                      bean                                                                           oil (4)                              W   --  -- --  "                          Epoxi-                                                                              Dioctyl  28.3                                                                              77.0                                                          dised                                                                               phthalate                                                                 soya (30)                                                                      bean                                                                           oil (4)                              __________________________________________________________________________

EXAMPLES 41-46

The examples in Table 13 illustrate the effect of gradually increasing the concentration of naphthalene oligomer. It can be seen that an increase in Oxygen Index occurs together with an improvement in flexibility as the concentration of naphthalene oligomer is increased.

                                      Table 13.                                    __________________________________________________________________________     Polyvinyl Chloride                                                                 Naphthalene                                                                              Parts of                                                         Ex- Oligomer  Naph-                  TEST                                      ample                                                                              Preparation                                                                           M. thalene                                                                             Phosphorus Ester                                                                        Stabiliser                                                                              RESULTS                                   No. No.    Wt.                                                                               Oligomer                                                                            (parts)   (parts) O.I.                                                                              IRHD                                   __________________________________________________________________________     41  10     440                                                                                5   Reofos (95) (50)                                                                        Dibutyl tin                                                                             34.6                                                                              87.0                                                               maleate (2)                                        42  10     440                                                                               10   Reofos (95) (50)                                                                        Dibutyl tin                                                                             43.7                                                                              84.5                                                               maleate (2)                                        43  10     440                                                                               15   Reofos (95) (50)                                                                        Dibutyl tin                                                                             57.8                                                                              80.0                                                               maleate (2)                                        44  10     440                                                                               20   Reofos (95) (50)                                                                        Dibutyl tin                                                                             71.3                                                                              78.0                                                               maleate (2)                                        45  10     440                                                                               25   Reofos (95) (50)                                                                        Dibutyl tin                                                                             72.1                                                                              73.5                                                               maleate (2)                                        46  10     440                                                                               30   Reofos (95) (50)                                                                        Dibutyl tin                                                                             74.4                                                                              70.0                                                               maleate (2)                                        __________________________________________________________________________

EXAMPLES 47-50

Table 14 illustrates the use of more than one phosphorus ester, together with a conventional PVC plasticiser or extender. In all examples an improvement in Oxygen Index occurs, and in Examples 47, 48 and 49 an improvement in flexibility also is achieved.

                                      Table l4                                     __________________________________________________________________________     Polyvinyl chloride                                                                 Naphthalene                                                                              Parts of                                                         Ex- Oligomer  naph-                        Extender/                                                                             TEST                         ample                                                                              Preparation                                                                           M. thalene                                                                             Phosphorus Ester                                                                               Stabiliser                                                                             Plasticiser                                                                           RESULTS                      No. No.    Wt.                                                                               oligomer                                                                            (parts)         (parts) (parts)                                                                               O.I.                                                                              IRHD                      __________________________________________________________________________     47  10     440                                                                               20   Reofos 95(20)                                                                         tris(2-chloro-                                                                          Dibutyl maleate                                                                        "Linevol" 79                                                                          54.9                                                                              66.0                                                ethyl)phosphate                                                                         (2)     tri-melli                                                     (5)              (25)                                X   --     -- --   Reofos 95(20)                                                                         tris(2-chloro-                                                                          Dibutyl maleate                                                                        "Linevol" 79                                                                          28.9                                                                              82.5                                                ethyl)phosphate                                                                         (2)     tri-melli                                                     (5)              (25) -48                                                                              10 440 20 Reofos                                                                  95(l5) tris(2-chloro-                                                          3Dibutyl                                                                       maleate "Linevol"                                                              79 66.2 65.5                                        ethyl)phosphate                                                                         (2)     tri-melli                                                     (10)             (25)                                Y   --     -- --   Reofos 95(15)                                                                         tris(2-chloro-                                                                          Dibutyl maleate                                                                        "Linevol" 79                                                                          30.5                                                                              79.0                                                ethyl)phosphate                                                                         (2)     tri-melli                                                     (10)             (25)                                49  10     440                                                                               20   Reofos 95(10)                                                                         tris(2-chloro-                                                                          Dibutyl maleate                                                                        "Linevol" 79                                                                          69.1                                                                              66.0                                                ethyl)phosphate                                                                         (2)     tri-melli                                                     (15)             (25)                                Z   --     -- --   Reofos 95(10)                                                                         tris(2-chloro-                                                                          Dibutyl maleate                                                                        "Linevol" 79                                                                          31.1                                                                              79.0                                                ethyl)phosphate                                                                         (2)     tri-melli                                                     (15)             (25)                                50  10     440                                                                               20   Reofos 95(20)                                                                         tris(2-chloro-                                                                          Epoxidised soya                                                                        Cereclor S52                                                                          73.4                                                                              78                                                  ethyl)phosphate                                                                         bean oil (4)                                                                           (25)                                                          (5)                                                  A.sup.1                                                                            --     -- --   Reofos 95(20)                                                                         tris(2-chloro-                                                                          Epoxidised soya                                                                        Cereclor S52                                                                          31.6                                                                              77.5                                                ethyl)phosphate                                                                         bean oil (4)                                                                           (25)                                                          (5)                                                  __________________________________________________________________________

The preparation of the oligomers used in the formulations of Table 15 is as described previously. However, except for Oligomer No. 38 the crude products were dissolved in toluene or chloroform and washed with water prior to steam stripping and vacuum stripping. Preparative and analytical data on these oligomers is given in Table 15.

Examination of Table 15 shows that all the compositions of the invention have superior Oxygen Index compared to the blank B'.

                                      Table 15                                     __________________________________________________________________________          Oligomer                                                                             Mol-                                                                               Parts                                                           Example                                                                             Preparation                                                                          ecular                                                                             of   Phosphorus Ester                                                                       Stabiliser                                                                           TEST RESULTS                                 No.  No.   weight                                                                             oligomer                                                                            (parts) (parts)                                                                              O.I.                                                                               IRHD                                     __________________________________________________________________________     51   31        20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          36.9                                                                               85.0                                                                 maleate (2)                                        B'   --    --  --   Reofos 95 (50)                                                                         Dibutyl tin                                                                          33.0                                                                               91.0                                                                 maleate (2)                                        52   32    650 20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          38.2                                                                               87.0                                                                 maleate (2)                                        53   33        20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          46.1                                                                               84.0                                                                 maleate (2)                                        54   34    550 20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          36.9                                                                               85.0                                                                 maleate (2)                                        55   35    500 20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          37.1                                                                               86.5                                                                 maleate (2)                                        56   36    470 20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          57.9                                                                               82.5                                                                 maleate (2)                                        57   37    410 20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          44.3                                                                               73.0                                                                 maleate (2)                                        58   38        20   Reofos 95 (50)                                                                         Dibutyl tin                                                                          38.2                                                                               89.0                                                                 maleate (2)                                        __________________________________________________________________________ 

What we claim is:
 1. A composition comprising a chlorine-containing aliphatic polymer and (a) an ester of a phosphorus acid, and (b) an aromatic hydrocarbon-containing oligomer of the formula

    (A).sub.a (--CH.sub.2 --).sub.b [--CH.sub.2 (OCH.sub.2).sub.m OCH.sub.2 --].sub.c (--CH.sub.2 X).sub.d

wherein A is at least one aromatic hydrocarbon-containing radical wherein the aromatic hydrocarbon moiety is selected from the group consisting of benzene, naphthalene and diphenyl ether, X is a member selected from the group consisting of --OH, --OR, ##STR22## phenoxy, benzyloxy and alkylphenoxy wherein R represents (1) a straight or branched chain alkyl having 1 to 12 carbon atoms, (2) cycloalkyl to 5 to 12 carbon atoms, (3) cycloalkenyl of 5 to 12 carbon atoms, or one of said groups (1) to (3) substituted by halogen, epoxy, nitro, amino, amido, ether, carboxyl, or ester groups, a is 2 to 20 but equals b+c+1, b is 0 to 19, c is 0 to 19, d is 0 to 2a and m is 0 to 10, there being at least two (--CH₂ X) groups per molecule, each --CH₂ O--CH₂ portion of the group [CH₂ (OCH₂)_(m) OCH₂ ] counting as (--CH₂ X) for this purpose, the said groups (--CH₂ --), [--CH₂ (OCH₂)_(m) OCH₂ --] and (-- CH₂ X) being bonded directly to a nuclear carbon atom of the aromatic hydrocarbon-containing radical.
 2. A composition as claimed in claim 1, in which m is
 0. 3. A composition as claimed in claim 1, in which A is unsubstituted other than by the said groups (--CH₂ --), [--CH₂ (OCH₂)_(m) OCH₂ --] and (--CH₂ X) or is substituted additionally by one or two groups selected from halogen, alkyl of 1 to 4 carbon atoms, haloalkyl of 2 to 4 carbon atoms, and the group OR³ where R³ represents hydrogen, alkyl of 1 to 4 carbon atoms or acyl of 1 to 4 carbon atoms.
 4. A composition as claimed in claim 1, in which greater than 50 mol % of radicals A are derived from naphthalene.
 5. A composition as claimed in claim 4, in which more than 75 mol % of radicals A are derived from naphthalene.
 6. A composition as claimed in claim 4, in which the naphthalene radicals are linked by (--CH₂ --O--CH₂ --) groups and the links are attached to the positions 1,4; 1,5; 1,6; 1,7; 2,5; 2,6 or 2,7 on the naphthalene nucleus.
 7. A composition as claimed in claim 6, in which the links are attached to the 1,4 or 1,5 positions on the naphthalene nucleus.
 8. A composition as claimed in claim 1, in which X is --OH, --OCH₃, --OC₆ H₅ or ##STR23##
 9. A composition as claimed in claim 1, in which the oligomer has a number average molecular weight of 300 to
 3500. 10. A composition as claimed in claim 9, in which the oligomer has a number average molecular weight of 350 to
 1500. 11. A composition as claimed in claim 10, in which the oligomer has a number average molecular weight of 400 to
 1000. 12. A composition as claimed in claim 1, in which the ester (a) is derived from phosphoric acid, phosphonic acid, phosphinic acid or phosphorous acid.
 13. A composition as claimed in claim 1, in which acid groups in partial esters are present as free acid groups or as a salt.
 14. A composition as claimed in claim 1, in which the ester (a) is an ester of pentavalent phosphorus.
 15. A composition as claimed in claim 14, in which ester (a) is a triaryl phosphate a tri-halo-alkyl phosphate a dialkyl aryl phosphate or a diaryl alkyl phosphate.
 16. A composition as claimed in claim 1, in which the polymer contains at least 5% chlorine.
 17. A composition as claimed in claim 16, in which the polymer contains more than 20% chlorine.
 18. A composition as claimed in claim 17, in which the polymer contains more than 40% chlorine.
 19. A composition as claimed in claim 1, in which the polymer is polyvinyl chloride, chlorinated polybutene, poly-chloroprene, poly-vinylidene chloride, chlorinated poly-4,4-dimethyl pentene, chlorinated polyethylene, chlorinated polypropylene, chlorinated polyethylene containing some chlorosulphonyl groups.
 20. A composition as claimed in claim 1, in which components (a) and (b) are present in a ratio of from 0.1 to 10 to 10 to 0.1.
 21. A composition as claimed in claim 20, in which the ratio of (a) and (b) is from 1:5 to 5:1.
 22. A composition as claimed in claim 21, in which the ratio of (a) and (b) is from 1:5 to 3:1.
 23. A composition as claimed in claim 1, in which 0.1 to 150 parts by weight of (a) plus (b) are used per 100 parts by weight of polymer.
 24. A composition as claimed in claim 23, in which from 2 to 100 parts of (a) plus (b) are used per 100 parts of polymer.
 25. A composition as claimed in claim 24, in which 5 to 25 parts of (a) plus (b) are used per 100 parts of polymer.
 26. A composition as claimed in claim 1, in which the oligomer (b) is admixed with a compound of the formula ACH₂ X where A and X are as defined in claim
 1. 27. A composition as claimed in claim 1, which also contains at least one member of the group consisting of a heat stabilizer, light stabilizer, antioxidant filler, pigment, lubricant, blowing agent, fungicide, Friedel Crafts catalyst or precursor thereof, extender, other fire retardant additive and smoke suppressant.
 28. A composition as claimed in claim 1, which also includes a phosphorus-free plasticizer in admixture with ester (a).
 29. A composition as claimed in claim 28, in which a phosphate ester is used with a phthalate ester or an adipate ester.
 30. A composition as claimed in claim 27, in which the phosphorus acid ester is present in a concentration of at least 50% in such mixtures.
 31. A composition as claimed in claim 30, in which the phosphorus acid ester is used in a concentration of at least 75%.
 32. A composition as claimed in claim 28, in which the phosphorus acid ester comprises a haloalkyl phosphate either alone or with an aryl phosphate, and the amount of phosphorus-free plasticizer is up to 90%. 